In recent years, the use of this skill in precision casting has been rapidly stagnated. This skill has obvious applications in reducing dopants, bridge holes and improving machine and processing functions of casting, losing the attention of more and more smelting enterprises. Rarely used as refractory filler without filtering with non-metal. The range of degrees of precision casting skills being improved is less due to how many ranges:

1, improved processing function: the reduction of dopant units in the non-metallic matrix can obviously improve the life of the cutting machine.

2. The international demand for high-quality castings increases rapidly, such as the rapid stagnation of the bus industry and the rise of the electric power generation industry.

3, the import casting for quality requirements, is to maintain precision casting position of great country, domestic smelting technology skills also lost rapid promotion, gradually to precision casting revitalization index forward, although the road is still long.

Household names, mixed is precision casting defects in the main top extremely kind of type, accounts for about half of the total to the shortcomings, is all castings to be able to have this shortcoming, but not with the significant level, for mixed faults to master the specification of the secondary casting based on the function, use and decide, the more elaborate casting, task environment mean the drawback of the castings for mixed restriction, the more severe, such as bus parts, start the machine casting, wind power castings, turbine castings, castings of tools.

In recent years, the domestic precision casting industry has been stagnant and rapid. The annual output of castings has been continuously upgraded, exceeding 28 million tons in 2006, far ahead of other countries. The domestic casting production increases rapidly, one scope is the international casting demand big width. Filtration skill is an ineffective technique for reducing and eliminating adulterants in smelting consumption. With the continuous improvement of smelting skill and casting quality in China, people's awareness of filtration skill has been deepening, so it will be used more and more widely.

Filter application criteria:

The ceramic foam filter has a large nominal volume, and the filter material has a strong adsorption for dopants. As the nonmetallic liquid flows through the agency's winding channel, the large dopant is simply absorbed onto the wall of the filter channel.

2, improve the machine function: flooding experiment, study indicates that because of the reduction of dopant, casting machine function, especially plastic.

3. Reduction of dopant defect: it is able to effectively reduce dopant units, reduce and eliminate such finished products.

4. Silica gel foam ceramic filters for heavy castings;

5, ceramic foam filter: made of foam plastic bone, coated with ceramic paste fired from, the best filtering effect, wide use.

In recent years, the smelting industry in China has been stagnant and rapid. The annual output of castings has been continuously upgraded, exceeding 28 million tons in 2006, far ahead of other countries. Because of the blocking effect of the filter on the non-metallic liquid and the blocking of all the mesh in the filtration process, the filtration area should be 3-4 of the original gate area.

1, just imagine casting bits, prevent non-metallic liquid splash, increase slag bag, extend the runne

2. Ensure the strength of the remaining core, adopt the resin process, and use special data at the fierce position of the heatstroke front;

3, the formulation of proper condensation, both ends to solve the process and strict operation in accordance with the rules;

4, the use of decent clean charge, prevent outdoor storage;

In the case of the cause of the contamination, there are secondary measures to eliminate this defect:

1. Secondary oxidation: because of the reason of casting structure or casting fragmentary assumption, strong spatter of non-metallic liquid in the pouring process constitutes secondary doping.

2. Improved process entry rate: the ineffective effect of filtration allows to simplify the simple pouring system originally conceived to eliminate adulterants and improve process product rate.

3, type, core sand strength: if the core sand strength is enough to resist the low temperature non-metallic fluid charging array, will form sand;

4. Coagulation and filtrate solution: in the process of incubation solution, spheroidization solution, refining solution, etc., residua will be formed into non-metallic liquid without proper process parameters and operation;

5, charge: if the charge rust or deposit is not when it will make the non-metallic liquid dopant content overwoven;

Mixed with: slag containing calcium carbonate and iron, manganese, aluminum oxide, unmelted inoculant particles, chloride, magnesium silicate, residual solvents, sand, etc.

The filter criterion can be placed in any position where the casting bits are being poured, but the closer the casting is to the filter, the better. In order to prevent low-temperature molten steel from crushing the filter at low pressure, the filter should be placed under the runner.

Benefits of precision casting filtration:

1. Machine filtration: when the non-metallic liquid sluggish filter is applied, the mixture larger than the aperture is blocked on the filter.

2. Filtering mechanism

3, silica gel ceramic foam filter is the latest emerging of a filter, than the general ceramic foam filter has better low temperature function, the manufacturing of the inch can be larger, filter heavy cast steel, cast iron parts, thermal storage coefficient is lower, for the head of the non-metallic liquid cooling. The rapid increase of domestic casting output is caused by the wide increase of international casting demand on one hand, and the result of the international transfer of smelting consumption in prosperous countries and regions on the other hand, which makes the casting import increase year by year.

How many kinds of filters are rarely used in precision casting?

1. Use filters, etc.

Filter cake: as the filtration stops, the filter hole will gradually become smaller and become blocked by impurities, thus filtering smaller impurities. There have been briefings using filtering skills in this country since the 1950's.

3, filtering, skills and experience the progress once stagnation: 60 times start using glass fiber filter, more than seventy year-end have sprung up pass filters, foam ceramic filter, 78, eighty times in honeycomb type filter, the use of filter skills is consumption quantity of high quality castings was once very minor process wrist, is east prosperous country lose their widespread use, its for the main sex consciousness also more and more deeply.

Taking foam ceramic filter as an example, the filtration mechanism is indicated as follows:

1, in the filter is the most effective measure to reduce the elimination of adulteration, bridge hole shortcomings.

2, group effect: non-metallic liquid is normally in the form of turbulent flow when pouring, when the filter after the non-metallic liquid tends to laminar flow form, is conducive to the rise of dopants, reduce the shape of the charge frame, reduce sand washing and secondary oxidation mixture.

3, glass fiber filter: made of low temperature resistant glass fiber cloth by special solution, poor filtering effect, cheap price.

At present, the use of new domestic smelting skills and new processes is mainly reflected in: more and more conservative molding lines and core manufacturing units, less and less use of resin sand process, casting steel VOD smelting, missing die smelting, computer simulation skills, and the use of rapid forming skills.